The subacute effects of caffeine (10mg/kg/day) were examined in a group of children selected from a school survey for habitual high or low dietary caffeine intake. The two groups differed in measures of autonomic arousal of caffeine (lower arousal for the high caffeine consumers) and in their response to daily caffeine supplement of their diet (high caffeine consumers exhibited fewer adverse side effects). The effects of glucose, sucrose (1.75gm/1g), aspartame (80mg/kg) and saccharin are being compared in a group of preschool children considered to have adverse behavioral responses to sugar or aspartame.